It's an unusually busy year for strandings, IFAW says

Marine mammal strandings in 2017 have been unusually high for the International Fund for Animal Welfare’s (IFAW) Marine Mammal Rescue and Research team.

In the most recent episode, 12 stranded dolphins were rescued from the mudflats of Wellfleet’s Herring River Gut at low tide on Oct. 18 and safely released at Herring Cove Beach in Provincetown by IFAW staff. Two other stranded dolphins died at the scene.

Marine mammal rescue and research personnel received a report of dolphins swimming in the area at approximately 2:30 p.m. that day. Local volunteers monitored the animals and provide staff with further details.

At about 4 p.m., with the tide receding, the dolphins began to strand. Volunteers and staff used damp blankets to prevent sunburn, positioned the dolphins’ bodies upright to help with breathing and kept birds away to prevent injuries.

The team used specially designed stretchers and carts to transport the live dolphins to two trailers that serve as part animal ambulance, part laboratory and part emergency room for health assessments and analysis before release, Branon said.

Following health exams, vitamin injections and blood analysis, they were transported to Herring Cove, a common release site. By 8:30 p.m. all 12 surviving dolphins were released and swimming freely out to deeper water.

One dolphin was fitted with a satellite transmitter on its dorsal fin to track its progress and was located offshore at 10 p.m. that night.

Necropsies will be performed on the two who died to help determine cause of death.

Four dolphins were examined and moved to Herring Cove in Provincetown, where they were released. Unfortunately, one of the smallest animals was severely malnourished and in poor health. After a thorough physical examination, the difficult decision was made by IFAW’s responding veterinarian to humanely euthanize the animal.

Two days later, two harbor porpoises stranded at Duck Creek, also on the bay side in Wellfleet. IFAW said its team does not typically see mass stranded harbor porpoises, however, occasionally they are found in pairs.

One porpoise had stranded on shore and the other was swimming in shallow water. IFAW worked with the Wellfleet Harbormaster to herd the swimming animal out to deeper water. The larger of the two animals was rescued and assessed for overall health. After an ultrasound exam was performed, our staff determined she was pregnant.

She was carefully released in Duck Harbor, where she had good, quick access to deep water.

Hours later the second harbor porpoise stranded. IFAW’s rapid response and quick health assessment allowed the porpoise to be transported and released near the same area the first porpoise was released, in the hopes that the two animals would rejoin and swim out of the area.

In the midst of the porpoise responses, the team received another hotline report of two common dolphins at Chapin Beach, Dennis. After recovering the lone dolphin, a health assessment was performed and the animal was cleared for release at a beach with open water access.

The next morning, seven more common dolphins were reported swimming in the shallow waters of Loagy Bay in Wellfleet. The tide was going out, and the IFAW team attempted to herd the animals to safety in deeper water. The attempt was ultimately unsuccessful and the dolphins stranded on the mud flats. Unfortunately, two dolphins died shortly after they stranded before rescuers could recover them. The other five were rescued and assessed for injuries and illness. Among the five rescued dolphins were a mother and calf.

A few days later four dolphins were found stranded off Dyer Prince in Eastham. One was dead on arrival, the other three were rescued, and assessed for health. Ultimately, predation by gulls resulted in wounds too severe to overcome in one young animal. That dolphin was humanely euthanized. IFAW advises those who find stranded dolphins to keep gulls away because they will attack the eyes, blowholes and other soft tissue. The remaining two were released at Scusset Beach in Sandwich, Massachusetts.

Due to the high number of stranded animals, IFAW’s experts are investigating each event and hopes to know more once results from clinical test are received. Cape Cod is a global hot spot for dolphin mass strandings. Unlike strandings in recent years, these recent events appear to be somewhat different, said IFAW.

One significant difference is that these dolphins are primarily females with calves, versus the norm over the last decade of a high proportion of young males. These females and calves seem to be exhibiting higher levels of stress and shock, and many are not surviving the initial physical impacts of the strandings like dolphins have in previous years.

There are a variety of reasons that factor into what causes dolphins to strand and the exact causes in these cases remains unknown.